The use of alkoxyated non-ionic as surface active agents is well known. The ethoxylation of fatty alcohols results in compounds that have both water soluble and oil soluble groups. The result is a so called “surfactant”, a contraction for surface active agent. The addition of ethylene oxide to fatty alcohol results in increasing water solubility.
The term “HLB” was first employed by the lab staff of the Atlas Powder Co. in America. This means the balance between the oil soluble and water soluble moieties in a surface active molecule, and is expressed as the “Hydrophile-Liphophile Balance”. A more oil-soluble emulsifier shows a lower HLB and a more water-soluble emulsifier shows the reverse. HLB is a very useful method in selecting an emulsifier, but it still has several limitations to application for every surfactant.
The HLB system developed by Griffin some 50 years ago. The system depends upon the observation that the solubility of the surfactant is related to the percentage by weight of polyoxyalkylene portion of the molecule and is relatively independent of the nature of the fatty group.